Power transmitter



Oct. 10, 1939.

N. F. TOWNSEND POWER TRANSMITTER Filed March 30, 1938 3 Sheets-Sheet l M ra a :1 A TTORNEYS.

Oct. 10, 1939. N. F. TOWNSEND 2,175,415

POWER TRANSMITTER Filed March 30, 1938 3 Sheets-Sheet 2 INVEN7:0R.---

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A TTORNEYS.

Get. 10, 1939. T D 2,175,415

POWER TRANSMITTER 3 Sheets-Sheet 3 Filed March 30, 1958 Patented Oct. 10, 1939 UNITED STATES PATENT OFFiCE POWER TRAN SHUTTER York Application March 30, 1938, Serial No. 198,952

6 Claims.

This invention relates to new and useful improvements in power transmitters especially adapted for use in conjunction with sewing machines, although also useful for other purposes.

Generally the object is to provide an efficient, simple and inexpensive transmitter which may be readily and effectively adjusted to take up slack in the belt by which the driving pulley of the transmitter is actuated from a line shaft or other source of power. More specifically the object is to provide a transmitter having a frame carrying the driving and driven pulleys, which frame and the parts mounted thereon are adjustable about a pivotal axis along one side or edge of the frame by adjusting means located at the other side or edge thereof.

The preferred embodiment of the invention is illustrated in the accompanying drawings, where- Fig. 1 is a perspective View;

Fig. 2 is a side elevation looking from the right of Fig. 1 and showing a work bench or table in transverse section;

Fig. 3 is a detail perspective view of an adjustable crank pin on the brake lever;

Fig. 4 is a perspective view of the brake-lever;

Fig. 5 is a top elevation of the transmitter hanger;

Fig. 6 is a detail perspective view of a pivot screw;

Fig. '7 is a plan view of the transmitter frame showing also several associated parts;

Fig. 8 is a detail perspective view of the bolt or screw for adjusting the position of the transmitter frame;

Fig. 9 is a vertical sectional View of the hanger frame on line 9-9 of Fig. 5;

Fig. 10 is a front elevation of the transmitter frame;

Fig. 11 is a view from the left of Fig. 1 showing several of the movable parts in elevation and the transmitter shaft in transverse section;

Fig. 12 is a vertical longitudinal section through the transmitter shaft and associated parts;

Fig. 13 is a perspective view of the transmitter shaft and Fig. 14 is a diagrammatic view showing relative positions of a pulley on a line shaft, the driving pulley of the transmitter, and the connecting belt.

Referring to the drawings:

(Fig. 2) is a bench or table suitable for the mounting thereupon of a sewing machine (not shown) and having therethrough openings 2|, 22 for the passage of a belt 23 (preferably round or circular in cross-section) from the transmitter supported from the under side of the table to the sewing machine mounted on the top side of the table.

A hanger of reverse L-shape and comprising the hanger and a horizontal screw-threaded opening through each lug is traversed by bearing screw 29 (Fig. 6) having a tapered end and also carrying a lock-nut 30 for securing the screw in adjusted position.

A transmitter frame having the outline of a reversed L in top plan view (Fig. 7) comprises a long arm 3! and a short arm 32, the long arm fitting lengthwise between the depending lugs 21 and 28 of the hanger, with the tapered ends of the bearing screws 29 engaging respectively in corresponding openings 33 and 34 (Fig. '7) in the vertical end faces of the arm 3! of the transmitter frame. The transmitter frame is thus pivoted to the hanger to swing about or be adjusted on an axis common to the pivot screws \25 29, 29. An adjusting bolt 35 (Fig. 8) passes downwardly through a slot 36 in the outer end of arm 25 of the hanger and a head 3'? at the upper end of the bolt carries a transverse pin 38 projecting at opposite sides of said head and bearing upon the bottom concave surface of two recesses 39 and 4!] in arm 25, said recesses being positioned on opposite sides respectively of the slot 35. Bolt 35 extends downwardly freely through a slot 4! (Figs. 2, '7 and 10) in the outer end of arm 32 of the transmitter frame, and at its lower projecting end carries a hand-operated nut 42, the upper end surface of which bears against a flattened surface 43 on the under side of said arm 32 of the transmitter frame.

As will be readily understood, turning of the hand-operated nut 42 will swing the transmitter frame about the axis of the pivot-screws 29 and 29 to adjust its position. A set-screw 44 (Fig. 2) passing through a threaded opening in lug 45 (see Figs. 1 and 10) projecting horizontally and outwardly from the side of the short arm 32 of the transmitter frame seats at its upper end against the surface 46 on the under side of the arm 25 of the hanger, and locks the transmitter frame in any position to which it may be adjusted by the hand-operated nut 42. To change the position of adjustment, the set-screw 44 is first loosened, the nut 42 then operated, and the screw 44 again tightened.

The transmitter frame includes two depending arc-shaped arms 50 and 5| at opposite ends thereof respectively, the arm 5| being somewhat wider at its upper end than arm 59 and said arms being connected by the web portion 52 of the frame which depends from the under side of the long arm 3| of the upper part of the transmitter frame. As shown in the drawings, said upper part of the frame, the depending arms 58, 5|, and the web portion 52, are

preferably cast in one piece and constitute a very rigid and durable transmitter frame for carrying the movable parts about to be described.

55 is a hollow or tubular non-rotatable transmitter shaft or axle supported at its opposite ends in openings through the lower ends of the arms 50 and 5| respectively and fixedly secured to each arm by a set-screw 56 (Figs. 1 and 2) at the lower end of the arm, said screws having tapered inner ends engaging depressions 51, 51 in the surface of the shaft 55 (Figs. 12 and 13). The shaft is closed (not bored through) at its right-hand end; and at its left-hand end carries a Well known type of lubricant cup 58 communicating with the space within the shaft which constitutes a reservoir for suitable lubricating oil or grease. Along the underside of the shaft, in the position in which the shaft is shown in Fig. 12 and which it assumes in the assembled transmitter, a longitudinal slot 59 is formed through the wall of the shaft to the lubricant reservoir and said slot is filled with leather 69 or other suitable lubricant feeding material.

Between the arms 58 and 5B of the transmitter frame, the shaft 55 carries the following parts located or mounted thereon (reading from left to right Fig. 12) :6| is the hub-like end of a starting lever 62, and 63 is a ball-thrust hearing. 64 is a driving pulley having an elongated hub, two belt-engaging surfaces of different diameters, and a fiat vertical frictional surface or face 65 at its right-hand end. 66 is a driven pulley also having an elongated hub, a belt groove at its periphery, and a friction surface at its left-hand vertical side or face provided by an annulus 6'! of leather secured in a groove or recess in the metal web of the pulley. 68 is another ball-thrust bearing between the pulley 66 and the arm 5| of the transmitter frame.

Three spaced cam projections or lugs "E6, each having oppositely inclined end surfaces (Fig. 11') on the vertical left-hand face of the hub-like end 6| of the starting lever 62, are adapted to cooperate with three similar cam lugs H on the vertical right-hand face of the lower end of the arm 50 of the transmitter frame.

A coiled spring 12, having its lower end connected to lever 62 by being hooked through an opening (Fig. 11) in the outer end of said lever, and its upper end connected to a pin 13 (Figs. 1 and on the web-portion 52 of the transmitter frame, continually tends to pull the outer end of lever 62 upwardly to a position in which the cam projections '10 on the hub-like end of said lever are respectively opposite spaces betweeen the cam projections "H on the arm 58 of the transmitter frame, so that the driving pulley is not forced into clutching engagement with the driven pulley and the transmitter is inactive. In this position of the parts, a brake-shoe l5, preferably of leather, is also held in braking engagement with the peripheral surface 16 of the driven pulley 66.

The brake lever or frame is shown in perspective in Fig. 4 and comprises two approximately parallel side arms 11 and 18, joined at their upper ends by a bridge piece 19 which partly spans the periphery of the driving pulley 64 and the belt thereto from a source of power. The brake lever is fulcrumed on two pins 80, 8| (Fig. 1)

having a common axis, the pin 88 extending from an opening 82 in the arm 11 of the brake lever (Fig. 4) into an opening 83 of the depending arm 56 of the transmitter frame (Fig. 10) and the pin 8| extending from an opening 84 in the arm 18 of the brake lever into an opening 85 of the arm 5| of the transmitter frame. At their lower ends, beneath the axis of oscillation which axis extends through the pins 80, 8|, the arm 18 of the brake lever carries the brake shoe (Fig. 4) before mentioned, and the arm 11 carries a crank pin (Fig. 3). One end portion 86 of said pin engages an opening through the enlarged lower extremity of arm 11, and the other portion 81 of said pin engages a notch 88 of the hub-like portion 6| of lever 62 (Figs. 1 and 11). The portion 81 of the crank-pin is eccentric to portion 86 thereof, and there are two transverse perforations 89 (Fig. 3) through the end portion 87, said perforations intersecting at right angles to each other. By loosening a screw 96, which contracts the split end of the head at the outer end of the arm 11, the grip on the portion 86 of the crank pin may be released and the pin rotated by engagement of a small nail or suitable tool in one of the openings 89. The crank-pin may thus be rotated to change the position of the portion 81 with relation to the notch 88.

9| (Figs 1 and 11 is a treadle rod depending from the outer end of the treadle lever 62 to a foot treadle (not shown) on the floor.

62 is a dress-guard spanning pulleys 64 and 66 and secured at its left-hand end to the lower end of arm 5!) by a screw 93 (Fig. 1) and its right-hand end to the lower end of arm 5| by a similar screw (not shown).

94 is a flat belt (partly shown in Fig. 2) leading from a pulley 95 on a line shaft to the driving pulley 64 of the transmitter, as shown diagrammatically in Fig. 14. If the pulley 95 happens to be located at a higher elevation than in Fig. 14, for example, such as to elevate belt 94 to the position shown in dotted lines 94a in Fig. 2 then the path of the belt may lead between the side arm 11 and I8 and beneath the bridge piece 19 of the brake-levers or frame, as also shown in Fig. 2.

In operation and assuming that the transmitter is installed in conjunction with a sewing machine (not shown) mounted on the upper side of bench 20, to transmit driving power to said machine,- the spring 12 normally holds the outer end of starting lever 62 elevated and this results in applying the brake-shoe 15 to the peripheral surface '16 of the driven pulley 66 and prevents the latter from rotating. Pressure upon the foottreadle (not shown) pulls treadle rod 9| downward, swings lever 62 downward against the tension of spring 12, rotates the brake lever to release the pressure of brake-shoe 15 upon the periperal surface of the driven pulley 66, rotates the cam projections or lugs 18 on the hub of lever 62 in relation to the fixed cam projections or lugs ll on the arm 58 of the transmitter frame, and thereby shifts the driving pulley 64 endwise along shaft 55 until the vertical surface 65 of pulley 64 is forced into gripping engagement with the driven pulley 66 and rotates the latter to drive the sewing machine through belt 23. Should the driving belt 94 to the driving pulley 64 become stretched or too loose for any reason, the position of pulley 64 may be adjusted or changed to take up the slack. The limits of such adjustment are shown by the full line position of the pulley 64 in one direction (Figs. 1 and 14) and its dotted line position in the other direction. As before explained, the desired adjustment of pulley 64 may be readily and quickly accomplished by first loosening set screw 44, then turning hand operated nut 42 and finally again tightening set screw 44. Both the set screw 44 and the nut 42 are easily accessible without removal of any other part at the righthand end of the transmitter mechanism, as best shown in Fig. 1.

Any desired tightening of belt 23 may be readily accomplished by disconnecting its ends, removing a section at one or both ends, and then reconnecting these ends.

In instances where the adjustment feature of the transmitter may not be needed, the hanger and its pivot screws 29, 29 may be omitted and the transmitter frame secured directly to the underside of the table. Under such conditions the three bolts or screws previously mentioned as engaging in the three interiorly screw threaded holes 26 of the hanger engage in three interiorly screw threaded holes 26' in the transmitter frame, the holes 26 being located in relative positions corresponding to the location of the holes 26. If the transmitter is originally installed without the hanger and the adjustment feature then becomes desirable, the hanger may be installed and the transmitter frame pivoted thereto by the bolts 29, 29 without the necessity of boring new holes in the table for the securing bolts.

What is claimed as new is:

1. Apower transmitter includingin combination, a hanger member or frame adapted to be rigidly secured to a supporting bench or table; a transmitter frame depending from said hanger mem-- ber and secured thereto by an approximately horizontal pivotal connection. at one side of said transmitter frame and on which the latter is adapted to be adjusted about the horizontal axis of said pivotal connection; transmitter mechanism parts carried by said frame and including a shaft and driving and driven pulleys on said shaft; and means for adjusting said transmitter frame about said pivotal connection, said transmitter frame and the parts carried thereby being detachable from said hanger member and adapted to be secured to a supporting bench or table for use as a non-adjustable transmitter.

2. Apower transmitter includingin combination, a hanger member or frame adapted to be rigidly secured toa supporting bench or table; a transmitter frame depending from said hanger member and secured thereto by an approximately horizontal pivotal connection at one side of said transmitter frame and on which the latter is adapted to be adjusted about the horizontal axis of said pivotal connection; transmitter mechanism parts carried by said frame and including a shaft and driving and driven pulleys on said shaft; means for adjusting said transmitter frame about said pivotal connection; and means for locking said transmitter frame in any position to which it may be adjusted, said transmitter frame and the parts carried thereby being detachable from said hanger member and adapted to be secured to a supporting bench or table for use as a non-adjustable transmitter.

3. Apower transmitter including in combination, a hanger member or frame adapted to be rigidly secured to a supporting bench or table; a transmitter frame depending from said hanger member and secured thereto by an approximately horizontal pivotal connection at one side of said transmitter frame and on which the latter is adapted to be adjusted about the horizontal axis of said pivotal connection; transmitter mechanism parts carried by said frame and including a shaft and driving and driven pulleys on said shaft; means for adjusting said transmitter frame about said pivotal connection, said means including a screw-threaded member depending from said hanger and a nut on said screw threaded member engaging the underside of said transmitter frame, said transmitter frame and the parts carried thereby being detachable from said hanger member and adapted to be secured to a supporting bench or table for use as a nonadjustable transmitter.

4. Apower transmitter includingin combination, a hanger member or frame adapted to be rigidly secured to a supporting bench or table; a transmitter frame depending from said hanger member and secured thereto by an approximately horizontal pivotal connection at one side of said transmitter frame and on which the latter is adapted to be adjusted about the horizontal axis of said pivotal connection; transmitter mechanism parts carried by said frame and including a shaft and driving and driven pulleys on said shaft; means for adjusting said transmitter frame about said pivotal connection, said means including a screw-threaded member depending from said hanger and a nut on said screw threaded member engaging the underside of said transmitter frame; and means for locking the transmitter frame in any position to which it may be adjusted, said means including a set screw engaging upwardly through a part of the transmitter frame projecting forwardly of its pivotal axis with the upper end of said set screw bearing against said hanger, said transmitter frame and the parts carried thereby being detachable from said hanger member and adapted to be secured to a supporting bench or table for use as a non-adjustable transmitter.

5. A power transmitter including a hanger member having openings therein, fastening means engaging said openings for securing said member to a supporting bench or table; a transmitter frame depending from said hanger member and secured thereto by an approximately horizontal pivotal connection and having openings therein corresponding in location to said openings in the hanger member; transmitter parts carried by said transmitter frame; and means for adjusting the transmitter frame about its pivotal connection to the hanger, said transmitter frame with the parts carried thereby being detachable from said hanger and adapted to be secured to a bench or table by fastening means engaging said openings in the transmitter frame.

6. A power transmitter including in combination, a hanger member or frame adapted to be secured to a supporting bench or table; a trans.- mitter frame pivotally supported from said hanger member; transmitter parts carried by said transmitter frame; and means for adjusting said transmitter frame about its pivotal connection to said hanger membersaid transmitter frame and the parts carried thereby being detachable from said hanger member and adapted to be secured to a supporting bench or table for use as a non-adjustable transmitter.

NORMAN F. TOWNSEND. 

